Raspberry variety named &#39;Korpiko&#39;

ABSTRACT

A new and distinct floricane fruiting red raspberry,  Rubus idaeus  L., variety is described. The variety results from selection among a population of seedlings derived from controlled pollination crossing of the raspberry varieties known as ‘Chilcotin’ (not patented) and ‘Waimea’ (not patented). The fruit of this new variety has an attractive appearance characterized by uniformly large berry size, good fruit firmness, and medium-red fruit color. The new variety is distinguished from others by its high yields of firm, attractive, uniformly sized, large, red berries that ripen in the mid season. The plant exhibits a semi spine-free upright growth habit, of strong vigor. In addition, the plant has displayed resistance to Raspberry Bushy Dwarf Virus (RBDV) under New Zealand conditions. Fruit of the new variety appears suitable for the fresh fruit market. The variety has been named ‘Korpiko’.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application No. 60/936,262 filed 19 Jun. 2007.

GENUS AND SPECIES OF PLANT CLAIMED

Rubus idaeus L.

VARIETY DENOMINATION

Korpiko

BACKGROUND TO THE INVENTION

The new variety of red raspberry, Rubus idaeus L., was created in the course of a planned breeding program carried out at Nelson, Motueka, New Zealand. The parents used to make the cross in 1990, were the varieties ‘Chilcotin’ (seed parent) (unpatented) and ‘Waimea’ (pollen parent) (unpatented).

Seed from this cross was grown and the original plant of the new variety was selected during the 1993-94 summer (Southern Hemisphere) and was found to exhibit:

-   (a) a semi spine-free upright growth habit of strong vigor, -   (b) the ability to form attractive large red fruit of good flavor in     high yields on medium length fruiting laterals that ripen mid     season, and -   (c) resistance to Raspberry Bushy Dwarf Virus (RBDV).

The new variety was first asexually propagated in 1998, being reproduced by vegetative cuttings arising from root cuttings. Cuttings developed this way in spring, root within a 3-4 week propagation period, and thus plants suitable for field planting are then ready in autumn of the same year. The resulting plants propagated true to type, demonstrating that the characteristics of the new cultivar are stable and are transmitted without change through succeeding generations. Since 2000, ‘Korpiko’ has been asexually propagated in vitro via tissue culture methods. The cultivar has propagated true to type via these means.

SUMMARY OF THE INVENTION

The new variety was selected from a population of seedlings derived from crossing the raspberry varieties known as ‘Chilcotin’ (not patented) and ‘Waimea’ (not patented). The new variety was assigned the breeder code, 90311BF-7 (subsequently coded HR6 at the advanced selection stage). The new variety has since been named ‘Korpiko’.

The new variety was tested and evaluated during the years 1996 to 2005 at Nelson Region, New Zealand (41.10°S, 172.97°E). The new variety has also been observed in test plots in Washington State, United States of America (USA).

When compared to the parent ‘Chilcotin’, the new variety was found to have larger, more conical shaped fruit of similar color, the larger fruit resulting in higher yields. ‘Korpiko’ is further distinguished from ‘Chilcotin’ by having fewer spines on canes.

When compared to the parent ‘Waimea’, the new variety exhibits fruit that are brighter red in color, that are larger and more conical in shape. ‘Korpiko’ also produces significantly higher cane numbers than ‘Waimea’ resulting in higher potential productivity and has more spines on canes.

Data collected during the evaluation period comparing fruiting performance of the new variety with standard New Zealand cultivars is presented in Table 1. TABLE 1 Comparison of fruiting and shelf life performance. 2003/04 season 2005/06 season Berry Berry Yield¹ weight Shelf Yield¹ weight Shelf Variety (T/ha) (g) life² (T/ha) (g) life² ‘Tadmor’ 25.9 4.5 36 13.7 4.7 50 ‘Korpiko’ 14.8 4 45 17.2 5.3 27 ‘Tulameen’ 17.1 4.1 63 12.9 4.2 76 ‘Motueka’ 21.3 2.7 15.3 3.8 ‘Moutere’ 17.4 3 63 14.2 4.5 48 ‘Korere’ 19.5 2.8 30 13.20 3.80 48 ‘Awaroa’³ 15.6 3.1 14.4 4.1 62 ¹Hand-picked ²Mean (10 berries × 3 reps × 3 harvests) cumulative percentage of berries with rot caused by Botrytis after 72 hours on the shelf at ambient temperatures (15-20° C.). ³‘Awaroa’ is a dual cropper i.e. the fruit is borne on both the current and previous year's growth; the data shown in Table 1 indicates the floricane fruit yield only.

Berries of the new variety are suitable for consumption as mid season, high-grade fresh fruit.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying photographs show typical specimens of the plant, foliage and fruit of the new variety as depicted in colors as nearly true as is reasonably possible to make the same in a color illustration of this character. The photographs were taken on mature plants in Nelson Region, New Zealand and Washington State, USA.

FIG. 1 shows fruit of the variety ‘Korpiko’

FIG. 2 shows a sample of individual fruit of the variety ‘Korpiko’alongside a scale indicating fruit size

FIG. 3 shows close-up views of typical individual fruit of the variety ‘Korpiko’ on a 1 cm×1 cm grid

FIG. 4 shows a close-up view of a fruiting lateral, including fruit, of the variety ‘Korpiko’ on the plant.

FIG. 5 shows the leaf and shoot tip of a fruiting lateral of the variety ‘Korpiko’

FIG. 6 shows a primocane tip of a cane of the variety ‘Korpiko’; view is of the upper and lower surface of the leaves.

FIG. 7 shows a floricane leaf of the variety ‘Korpiko’; view is of the upper and lower surfaces

FIG. 8 shows a plant of the variety ‘Korpiko’ in the field; view is of the post-flowering, early fruit set stage.

FIG. 9 shows a fruiting plant of the variety, ‘Korpiko’ in the field; the large fruit size, high productivity, and the productive, medium length fruiting laterals are displayed.

DETAILED DESCRIPTION

Horticultural terminology is used in accordance with UPOV guidelines for raspberry. All dimensions in millimeters, weights in grams (unless otherwise stated). Where a color reference is given these refer to the RHS Color Chart, The Royal Horticultural Society, London. 4^(th) Edition, 2001. The specimens described were grown at HortResearch Nelson, New Zealand and in Washington State, USA.

Environmental data for the New Zealand growing area demonstrates conditions in spring and early summer (equating to the harvest period for the cultivar) as follows:

Spring (September/October); mean daily temperature in the range 10-12° C. (mean daily minimum 5.8° C., mean daily maximum 16.5° C.).

Early summer (December/January); mean daily temperature 16.8° C. (mean daily minimum 11.1° C., mean daily maximum 22.4° C.).

A cool temperate area, frost conditions are typically experienced in winter, with the lowest winter air temperature unlikely to be colder than −6° C. Average annual rainfall is approximately 1125 mm.

-   Plant and foliage: Plants exhibit a strong and medium upright growth     habit (FIGS. 8 and 9). Mature plant height is commonly in the range     2000 mm to 2500 mm, although this may vary with the growing     conditions. Strong vigor is exhibited and internode length is     typically long and in the range 110-130 mm. Plants have many young     shoots; canes have many spines near the base and few near the top of     mature canes. Spines (prickles/thorns) are sparse, particularly on     the upper cane section and are small on mature canes (typically     approximately 1 mm long), but may be denser and longer on juvenile     canes. Plants have been observed to be less spiny compared with some     other commercial varieties, for instance, ‘Marcy’ (not patented).     Spine color is dark (near purple N79A). Canes are pubescent     indicating the presence of gene H. Canes typically show light     brown-tan coloration (near Greyed-orange 174A and Grey-brown 199B)     in winter. During the growing season some purple coloration (near     Red-purple 59A) is evident on the sun-exposed side of the cane.     Young shoots are erect and are near Yellow-green 144A in color.     Fruiting laterals are medium long typically 600-800 mm in length.     The leaves are compound, moderately crinkled, flat and moderately     dull, with strong silver coloration on the leaf underside. (FIGS. 6     and 7). The number of primocane leaflets per internode is both three     and five. The base of the terminal leaflet is rounded in shape and     typically averages 80 mm in diameter and 100 mm in length. The     coloration of the upper surface of the leaf is green (near     Yellow-green 146A), the under side being markedly lighter in     coloration (near Greyed-green 191A). While the leaves do not have     distinguished marginal or vein coloration, the venation has     noticeable rises and falls. The leaf petiole typically averages     approximately 105 mm in length and 2.5 mm in diameter. It is near     Yellow-green 144B in color. The fruit is borne on the previous     year's growth. The fruiting laterals are medium long in length,     commonly measuring 500-700 mm, and are weakly ascending and     horizontal when fruit has ripened. Fruit presentation at harvest     time is excellent and well suited to hand-picking. -   Inflorescence: White flowers are borne on short slender pedicels     with sparse spines (thorns/prickles). At Nelson Region, New Zealand     the date bud burst commences is approximately 8 September, with     fifty percent of buds burst by mid-late September (approximately 22     September). The time of bloom is mid season for a summer-fruiting     raspberry, with peak flowering around mid November. Flowers are     numerous and borne on a paniculate inflorescence. Typically there     are five petals, elongated ovate in shape with a rounded apex and     flat base. The petals average approximately 7.1 mm in length and 3.4     mm in width. They are typically smooth in texture, have a smooth     margin and are near White 155C in color. The pedicel length averages     approximately 17.0 mm long. However, the more basal the pedicel the     longer it commonly becomes with pedicel lengths up to about 50 mm     being observed. The pedicel averages approximately 1.1 mm in     diameter and is near Yellow-green 144A in color and has weak     anthocyanin coloration on the sun-exposed side. A typical king     flower diameter is approximately 29 mm (from sepal tip to sepal tip     i.e. the widest part of the flower). The flowers are predominantly     borne singly, although sometimes in clusters of two or more.     Terminal branch flower clusters frequently consist of two flowers     and basal flower clusters may number three to five. The flowers have     no discernible fragrance. Five sepals are present. These are green     in coloration (near Yellow-green 144A on the bottom and near Green     138C on top) and measure approximately 15 mm in length from base to     tip. The reproductive organs are typical for flowers of Rubus idaeus     L.; the stigmas average approximately 95 in number and are near     Yellow-green 145C in color; there are approximately 90-95 stamens     the filaments which are near White 155D in color and average 4.4 mm     in length. Anthers are brown and (depending on maturity) near Brown     200D in color. -   Harvest: Fruit commences ripening in mid December in New Zealand.     The typical start date for picking the new variety is 13 December.     Fifty percent of the harvest is typically completed by 28 December,     and the main harvest period is complete by mid January     (approximately 18 January). ‘Korpiko’ is not suitable for harvest by     machine due to the moderately strong force required to dislodge the     berry from the receptacle. ‘Korpiko’ is recommended for mid season     production for fresh market fruit. The variety may also be suited to     long cane production systems due to its high quality fruit and     suitability to fresh markets. -   Fruit: Fruit is produced on previous year's cane in summer. Berry     size is large. The average berry weight is approximately 4.5 g;     individual fruit ranging between 4-6 g in weight (Table 1). Fruit     shape is conical; on the basis of fruit length to width ratio, fruit     is much longer than broad (FIG. 3). On average berries are 25 mm     long and 20 mm wide at the widest point. Fruit color is medium red;     external color near Red-46A, internal color near Red 46A. Fruit     color of ‘Korpiko’ fruit has been observed to differ to that of     another commercial red raspberry variety, ‘Skeena’ (not patented),     which has medium dark red fruit. The fruit skin of ‘Korpiko’ fruit     shows medium to high glossiness as a result of hairs present.     Attractive large conical shaped fruit and the presence of fine hairs     on the fruit skin are distinctive features of the new variety. Fruit     drupelet size has been observed to be medium compared with drupelet     size of fruit of another commercial red raspberry variety, ‘Glen     Ample’ (not patented) which are large. Drupelets number typically 95     and are quite large, typically 4.5 mm in diameter. Fruit size is     uniformly large through the harvest maturity period. The berries are     medium firm and of good raspberry flavor. The seeds average 3.0 mm     long and 1.6 mm wide, and are near Greyed-orange 164D in color when     dry. Seed numbers per fruit average 95 and weigh on average 0.14 g     per fruit (or average 1.5 mg individually). Fruit quality is largely     due to the fruit having a firm and fleshy-texture with good flavor.     ‘Korpiko’ fruit has been observed to have a good shelf life in     Nelson Region, New Zealand (Table 1). Fruit shelf life appears     improved over the commercial varieties ‘Marcy’ (not patented),     ‘Skeena’ (not patented), and ‘Tulameen’ (not patented). Yield is     high, typically in the range 14-18 T/ha equivalent (Table 1). -   Pest and disease resistance: The plant does not seem to be     susceptible to yellow rust (Phragmidium rubi-idaei) and appears     resistant to Raspberry Bushy Dwarf Virus (RBDV). Since the selection     of this clone in 1993-94 numerous tests for RBDV have been carried     out on ‘Korpiko’ in New Zealand using ELISA, but on no occasion has     the virus been detected in spite of high infection pressure. From     this we suggest that ‘Korpiko’ is likely to be resistant to the     common strain of RBDV found in New Zealand. Resistance to aphids is     unknown. -   Geographical adaptation: Observations indicate that the variety is     well-suited to production in regions that offer a medium amount of     winter chill, for example, ‘Korpiko’ performs well in the cool     temperate region of Nelson, New Zealand under standard management     practices for commercial raspberry production. Initial indications     are that ‘Korpiko’ also performs well in USDA Plant Hardiness zones     8-10 (published as the 2003 US National Arboretum “Web Version” of     the USDA Plant Hardiness Zone Map USDA Miscellaneous Publication No.     1475, Issued January 1990). 

1. A new and distinct red raspberry plant as herein illustrated and described. 